dtoc: Tidy up property-offset handling

If a property does not yet have an offset, then that means it exists in
the cache'd fdt but has not yet been synced back to the flat tree. Use
the dirty flag for this so we don't need to check the offset too. Improve
the comments for Prop and Node to make it clear what an offset of None
means.

Also clear the dirty flag after the property is synced.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
index f0d1384..36993c2 100644 (file)
--- a/tools/dtoc/fdt.py
+++ b/tools/dtoc/fdt.py
@@ -103,6 +103,8 @@ class Prop:
     """A device tree property
 
     Properties:
+        node: Node containing this property
+        offset: Offset of the property (None if still to be synced)
         name: Property name (as per the device tree)
         value: Property value as a string of bytes, or a list of strings of
             bytes
@@ -114,7 +116,7 @@ class Prop:
         self.name = name
         self.value = None
         self.bytes = bytes(data)
-        self.dirty = False
+        self.dirty = offset is None
         if not data:
             self.type = Type.BOOL
             self.value = True
@@ -228,7 +230,7 @@ class Prop:
         Raises:
             FdtException if auto_resize is False and there is not enough space
         """
-        if self._offset is None or self.dirty:
+        if self.dirty:
             node = self._node
             fdt_obj = node._fdt._fdt_obj
             if auto_resize:
@@ -239,13 +241,15 @@ class Prop:
                     fdt_obj.setprop(node.Offset(), self.name, self.bytes)
             else:
                 fdt_obj.setprop(node.Offset(), self.name, self.bytes)
+            self.dirty = False
 
 
 class Node:
     """A device tree node
 
     Properties:
-        offset: Integer offset in the device tree
+        parent: Parent Node
+        offset: Integer offset in the device tree (None if to be synced)
         name: Device tree node tname
         path: Full path to node, along with the node name itself
         _fdt: Device tree object